Colonial law enforcement -- Police reform, 1829-1860 -- Varieties of criminal behavior: the 19th century -- Entrepreneurs, reformers, and the emergence of professionalism, 1870-1920 -- Federal law enforcement: the 19th century -- Law enforcement in the American West -- The triumph of reform: police professionalism, 1920-1965 -- Varieties of criminal behavior: the 20th century -- Organized crime in the 20th century -- The state police -- Federal Law enforcement: the 20th century -- Modern policing